This invention relates to a power supply system for supplying energy to vehicles (such as land vehicles, vessels and the like) having energy consuming equipment (such as radars, gun turrets, or radio transmitters) on board.
In vehicles of the aforenoted type it is advantageous to use a sole energy source, usually an internal combustion engine, such as diesel engine or a carburetor type engine which furnishes both the energy required for the propulsion of the vehicle and for the operation of the equipment and the associated auxiliary apparatus on board. In this manner, the weight and costs of an additional engine are saved. But, on the other hand, difficulties are encountered in view of the fact that the characteristics of the energy supply for propelling the vehicle and for operating the equipment on board are often very different from one another as far as conrol and output are concerned. This is particularly the case in a vehicle which is equipped with radars or weapon systems. The energy requirement (electric energy) of this type of equipment is less than that for propelling the vehicle, but the requirements relating to the characteristics of voltage and frequency control are extremely stringent. The control of a combustion engine, however, is efficient and accurate only for an output and an operational range which are of the same order of magnitude as the average output and average operational range of the engine. In practice, the output necessary for driving the vehicle is far greater than that required for the equipment on board and thus, the difficulties to obtain a satisfactory control tend to preclude the use of a sole engine. Also, it is often necessary to utilize an auxiliary vehicle which carries an energy source for supplying with energy one or several vehicles having the aforenoted equipment on board.
As it has been mentioned before, one of the difficulties in providing a sole engine that supplies the two types of energies resides in the inaccuracy of the control of the engine for substantially different output ranges. In general, in any type of engine, the specifications of the different engine accessories are determined for a sole output: the output at which the engine is to operate under normal conditions. Thus, in a combustion engine, the caliber of the engine accessories, the fuel feed input, the lubrication, the cooling system etc., are all matched with the same said engine output. An imbalance in the matching of one of these accessories, for example, the cooling system, causes not only a drop in the engine output down to the smallest output for which the accessory in question has been designed, but also, the accessory will operate in a defective manner at this reduced output. In particular, there will be experienced a lack of flexibility and stability of operation.